Located within Mammoth Mountain Ski Area but open to the public with no fee required, the Dragon's Back Hiking Trail, starting from the trailhead at the far end of the Twin Lakes Campground, is a steep and strenuous uphill hike with increasingly dramatic views of the Mammoth Lakes Basin the higher you get. Near the top of the ridge, peer back down toward Twin Lakes through a natural lava tube dubbed the "Bottomless Pit" or "Hole in the Wall." Take the Seven Lakes Point Trail to the end and see if you can name all seven lakes! Follow the Dragon's Back Hiking Trail up to the interpretive center at the top of Mammoth Mountain. Return the way you came or ride the scenic gondola to Main Lodge and catch a shuttle.